Thancred Waters

White has printed indestructible-granters before, but almost always as a one-shot combat trick or a fog-adjacent sweep dodge. This one turns the effect into a standing shield, and the mechanism is what makes it worth studying. The enters trigger fixes indestructible onto another legendary permanent you control for exactly as long as you control this: not a turn, not a phase, but a leash tied to the source. Kill the guard and the ward drops with it, which reframes what looks like protection as a two-permanent stack an opponent has to unravel in the right order. The flash keyword sharpens that further, letting the shield snap onto a legendary in response to a removal spell rather than being telegraphed a turn early. The second ability then guards the guard: casting any noncreature spell hardens this body until end of turn, so a deck already leaning on instants and enchantments keeps its protector alive through the damage-based and destruction-based answers that would otherwise peel it away first. That legendary-permanent clause anchors the whole card, aiming it squarely at a board full of legendary creatures, planeswalkers, and legendary artifacts rather than a generic white creature line. It is protection with a dependency, and the dependency is the point: it asks you to defend the defender.